1. Field of the Invention
The present invention relates to a typewriter, and more particularly to an electronic typewriter.
2. Description of the Prior Art
The typewriter has advanced from mechanical models to electronic models. The electronic typewriter can handle a large amount of information and store and maintain sentences and information necessary for typing. The information has titles assigned to it by an operator so that it can be readily registered and retrieved.
FIG. 1 shows the keyboard of an electronic typewriter. SSW denotes a slide switch which instructs registration of document information into a memory when it is at a rightmost position STR, and instructs retrieval of the document information from the memory when it is at another position. P.sup.. FORM denotes a key used to register or retrieve information for a page format, that is, tabulations and margins for a special format, S.sup.. FORM denotes a key used to register or retrieve information for a stop position format, that is, start position data for records on a specific slip, and TEXT denotes a key used to register or retrieve a document. INDEX denotes a key to instruct line feed, REVINDEX denotes a key to instruct reverse line feed, RTN denotes a key to instruct carriage return, * denotes a key to instruct a punctuation in a series of operations, and REPEAT denotes a key to instruct repetition of a key depressed immediately before.
FIG. 2 shows an external view of a display which comprises a 20-digit fluorescent display tube. The display tube of FIG. 2 is usually arranged on the top of the keyboard of FIG. 1 so that an operator can readily watch it.
FIG. 3 shows a flow chart for registering a document. In a step 3.1, the slide switch SSW is set to STR to instruct a new registration. In a step 3.2, the TEXT key is depressed, and in a step 3.3, a desired AS title is entered by character keys. In a step 3.4, the * key is depressed and in a step 3.5, the inputting of the document is started. After the document has been input, the TEXT key is again depressed in a step 3.6 to terminate the registration operation.
FIG. 4 shows a flow chart for retrieving the document in the prior art system. In a step 4.1, the slide switch SSW is set to a position other than STR to instruct the retrieval of the registered document by generating a document retrieval instruction. In a step 4.2, the TEXT key is depressed, and in a step 4.3, the title of the registered document is entered. It is apparent that the document cannot be retrieved if a correct title is not entered. After the title inputting step 4.3, the * key is depressed in a step 4.4 and in a step 4.5 the registered document is amended or additional data is input, and in a step 4.6, the TEXT key is depressed again to terminate the retrieval operation.
A disadvantage in the document retrieval operation described above is that the input title must be identical to the registered one. Thus, the operator must perfectly remember the registered title. This is a substantial burden to the operator when the number of registered documents is large.